直接奈米壓印結合反應式離子蝕刻在金薄膜/PMMA疊層上製作複合光柵

楊戩(Yang, Jian)

指導教授 ： 敖仲寧

國立中正大學/工學院/機械工程學系/碩士(2014年)

摘要

LCD背光模組中具偏振功能的導光板為金屬光柵與透光基材(PMMA)的疊層結構，以往此疊層結構皆以黃光製程製作，不僅製程時間冗長且過程繁雜。本研究利用抗沾黏層結合直接金屬奈米壓印，於矽基板上製備金屬光柵，並將製作出的金屬光柵以熱壓方式嵌入PMMA中製作出嵌入式複合光柵，接著以反應式離子蝕刻(RIE)進行乾式蝕刻移除金薄膜/PMMA複合光柵之金殘留層及進一步蝕刻部分PMMA而製作出可透光之金薄膜/PMMA複合疊層光柵，使其適用於液晶螢幕之背光模組中導光板的穿透式偏振片(WGP)。
研究過程中改善直接金屬奈米壓印製程，提高製作金光柵薄膜/矽疊層試片的良率，並大幅提高光柵成型性。而在嵌入式奈米壓印製程中，提高金光柵嵌入PMMA成為複合光柵的嵌入面積百分比，並透過調整RIE蝕刻參數壓力、通入氣體比例等達到較佳的蝕刻速率。
在金薄膜/PMMA複合疊層光柵的光學特性方面，本研究量測其穿透率，其中金薄膜/PMMA複合疊層光柵較高穿透率約22%，相較於未移除殘留層之嵌入式複合光柵的穿透率約2%，已有大幅提高。由於本研究模仁線寬受到曝光製程波長的限制，所以製備出來的複合光柵線寬400nm大於1/2可見光波長，尚無法在可見光範圍內產生偏振效果，但之後可藉由電子束微影系統製作出小於300nm的模仁線寬，便能在可見光波長下產生偏振效果。

關鍵字

金薄膜/抗沾黏層/矽基板疊層 ； 金屬/PMMA複合疊層光柵 ； 嵌入式奈米壓印 ； 直接金屬奈米壓印 ； 反應式離子蝕刻

並列摘要

The structure of light guide plate with polarization function in LCD backlight module mainly consists of metal grating and translucent substrate made of PMMA. In the past, the laminated light guide plate having metal grating and PMMA stacking feature has been fabricated so far by using a series of complicated photolithographic and conventional nano-processes. In this research, metal grating was fabricated on a silicon substrate using anti-adhesion layer by direct metal nanoimprint, and to produce the insertion composite grating by hot pressing the metal grating embedded in PMMA. Then we used Reactive Ion Etching (RIE) to remove the residual metal layer of the metal grating/PMMA stack structure. Finally making it suitable for the wire grid polarizer (WGP) applied to the LCD screen backlight guide plate can be efficiently fabricated.
By improving the load of direct metal nanoimprint, the yield rate of direct imprint of Au grating/Si specimens was improved, and satisfactory grating pattern was achieved, which further improved insertion nanoimprint quality and satisfactory. The yield of Au grating/PMMA specimens was increased. By adjusting RIE’s parameters such as pressure, the amount of etching gases, better etching rate can be obtained.
The optical properties of Au grating/PMMA bi-layered grating exhibited a transmittance value of 22 % compared to those specimens without etching exhibiting only 2% transmittance. Being limited by the photolithographic technique, the line width 400 nm of the mold for direct nanoimprint could not be made smaller than 1/2 wavelength of the visible light, therefore polarization effect could not be achieved so far in visible light range.

並列關鍵字

gold film/titanium film/anti-adhesion layer/silicon substrate stacking ； metal/PMMA bi-layered grating ； insertion nanoimprint ； Direct metal nanoimprint ； Reactive Ion Etching

參考文獻

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